Grapevine plant named ‘15-97-77’

ABSTRACT

This new grape plant named ‘15-97-77’ is distinct because of its unusual shape, very firm texture and very large berry size. Berries of the new cultivar are very responsive to applications of exogenous gibberellic acid, almost doubling in size in comparison to untreated fruit. At full maturity in mid-September, berries are extremely firm and sweet.

Genus and species: Vitis vinifera.

BACKGROUND AND SUMMARY OF THE INVENTION

The new grape plant named ‘15-97-77’ is of Vitis vinifera parentage. Itis the result of an effort to produce a late-ripening, black, seedlesstable grape with fruit characteristics superior to currently availableblack cultivars ‘Fantasy Seedless’ (unpanteded) and ‘Negrita’(unpatented). The female parent (unnamed) (unpatented) resulted from aseries of crosses involving ‘Hunisa’ (unpatented), ‘Emperor’(unpatented), and ‘Thompson Seedless’ (unpatented). The male parent ofthe cross is an unnamed (unpatented), seedless grapevine resulting froma series of crosses involving ‘Emperor’, ‘Thompson Seedless’, and‘Almeria’ (unpatented). The hybridization resulting in ‘15-97-77’ wasmade near McFarland, Calif. in 1994. Seeds from the cross werecollected, stratified, and finally planted in a greenhouse in January of1995. The seedling population of 60 plants was planted in the field inthe spring of 1995 near McFarland, Calif. The new grape plant wasselected from this seedling population in 1997. It was then propagatedby cuttings and grafting to ‘Freedom’ (unpatented) rootstock in 1998near McFarland, Calif. Those resulting plants were stable and typical ofthe original vine.

The new grape plant named ‘15-97-77’ is quite distinctive and unlike anyother table grape available on the market known to me. Its very largeberries are obovate and average over 10 g with applications of exogenousgibberellic acid. The large clusters average over 1500 g under standardcultural practices, but are quite loose and amenable to packing for coldstorage purposes.

COMPARISON WITH PARENTAL CULTIVARS

The new gape plant is similar to its female parent, but differs byhaving seedless rather than seeded berries. It differs from its maleparent by having berries with black skin rather than white skin.

DESCRIPTION OF THE FIGURES

The accompanying drawings illustrate the following:

FIG. 1 shows a fruit cluster on the vine.

FIG. 2 shows a cane, leaf, natural fruit cluster (left) and fruitcluster following gibberellic acid applications (right).

DETAILED BOTANICAL DESCRIPTION OF THE INVENTION

The following description of grapevine ‘15-97-77’ contains references tocolor names taken from The Munsell Color Chart for Plant Tissues,published by Munsell Color, New Windsor, N.Y. Descriptors used hereinconform to those set forth by the International Board for Plant GeneticResources Institute Grape Descriptors (Vitis spp.) of 1983 and/or 1997which were developed in collaboration with the Office International dela Vigne et du Vin (OIV) and the International Union for the Protectionof New Varieties of Plants (UPOV) and published in Descriptors forGrapevine (Vitis app.) (Anonymous, International Plant Genetic ResourcesInstitute, 1997, ISBN 92-9043-352-3).

Descriptions of the new invention apply to vines of ‘15-97-77’ grown on‘Freedom’ rootstock at a density of 1,537 vines per hectare grown inKern County, Calif. in 2001. These vines were in their first year offull production having been planted in 1998. These descriptions arebelieved to apply generally to the new variety grown under similarcircumstances elsewhere:

VINE

General:

Vigor.—High, vines spur-pruned and shoot thinned to 32 shoots average291 cm. of growth per cane.

Density of foliage.—Moderate.

Productivity.—Very productive when spur pruned, up to 70,610kg./hectare.

Hardiness.—Hardiness observed to 0 C.

Rootstock.—Freedom.

Trunk:

Shape.—Broadly elliptical.

Straps.—Long, split.

Surface texture.—Shaggy.

Trunk circumference.—12.5 cm. at 1 meter height.

Inner bark color.—2.5YR 5/6.

Outer bark color.—5YR 5/2.

LEAVES

Mature leaves:

Average blade length.—16.8 cm.

Average blade width.—20.3 cm.

Size of blade.—Large.

Shape.—Pentagonal.

Anthocyanin coloration of main veins on the upper side of theblade.—Absent.

Mature leaf profile.—Flat.

Blistering surface of blade upper surface.—Absent.

Leaf blade tip.—In plane of the leaf.

Margins.—Lobed, serrate, undulating.

Apex.—Broadly acuminate.

Bases.—Sagittate.

Thickness.—Medium.

Undulation of blade between main and lateral veins.—Slight.

Shape of teeth.—Conical, both sides convex.

Length of teeth.—5-10 mm.

Ratio length/width of teeth.—About 1:1.

General shape of petiole sinus.—Variable — open (ovate) to closed.

Tooth at petiole sinus.—Absent.

Petiole sinus limited by veins.—Absent.

Shape of upper lateral sinus.—Closed.

Prostrate hairs between veins on lower surface of blade.—Absent.

Erect hairs between hairs on lower surface of blade.—Absent.

Prostrate hairs on main veins on lower surface of blade.—Absent.

Density of erect hairs on main veins on lower surface of blade.—Sparse —hairs distributed along enite length of main veins.

Prostrate hairs on main veins on upper surface of blade.—Absent.

Upper surface:

Summer color.—7.5 GY 4/4 to 4/6.

Autumn color.—5Y 8/6.

Surface texture.—Smooth.

Surface appearance.—Dull.

Goffering of blade.—Absent.

Lower surface:

Summer color.—5GY 5/8 to 5/10.

Autumn color.—5Y 8/4.

Anthocyanin coloration of main veins on lower leaf surface.—Weak.

Glossiness.—Low.

Pubescence.—Absent.

Surface texture.—Smooth.

Surface appearance.—Dull.

Petiole:

Length of petiole.—15.0 cm.

Length of petiole compared to middle vein.—About equal.

Density of prostrate hairs on petiole.—Absent.

Density of erect hairs on petiole.—Sparse.

Shape of base of petiole sinus.—Mostly closed, inside outline is ovate.

Color.—In shade: 2.5GY 8/8. In sun: 5R 5/6.

TENDRILS

Number: Bifurcated and trifurcated, forming at all nodes above node 3.

Length: 26.1 cm.

Diameter: 2 mm.

Texture: Smooth.

Color: 5GY 7/10.

WOODY SHOOT

Cane:

Shape.—Broadly elliptical.

Internode length.—About 11.0 cm.

Width at node.—About 1.5 cm.

Cross section.—Circular.

Surface.—Smooth.

Main color.—5YR 5/6.

Lenticels.—Inconspicuous.

Erect hairs on nodes.—Absent.

Erect hairs on internodes.—Absent.

Laterals:

Shape.—Broadly elliptical.

Number.—Laterals forming at all nodes above node 4.

Length.—5.0-129.5 cm.

Diameter.—4-9 mm.

Internode length.—2-7.5 cm.

Color.—2.5YR 4/6.

Buds:

Shape.—Slightly pointed.

Cane bud fruitfulness.—Basal buds fruitful, 1-2 clusters per shoot.

Length.—5 mm.

Width.—5 mm.

Height.—6 mm.

Color.—5YR 4/6 .

Time of bud burst.—Mar. 18, 2003.

FLOWERS

General:

Flower sex.—Perfect.

Position of first flowering node.—Usually the 4^(th).

Number of inflorescences per shoot.—1 or 2.

Calyptra color.—5GY 7/8.

Ovary length.—2 mm.

Ovary width.—1.5 mm.

Ovary color.—5GY 4/8.

Filament length.—2 mm.

Filament color.—2.5GY 8/2.

Anther length.—1 mm.

Anther color.—2.5GY 8/8.

Date of full bloom.—May 8, 2001 in McFarland, Calif.

FRUIT

General:

Ripening period.—Late, about 1 month after ‘Thompson Seedless’ atDelano, Calif.

Date of ripening.—About Sep. 1, 2001.

Use.—Fresh market.

Keeping quality.—Very good.

Resistance.—Insects: typical of Vitis vinifera. Diseases: typical ofVitis vinifera.

Shipping quality.—Good.

Date of first harvest.—Sep. 1, 2001.

Solids-sugar.—High, about 20 brix at full maturity.

Refractometer test.—23.0 brix.

Cluster:

Bunch size.—Large.

Bunch length (peduncle excluded).—About 34 cm.

Bunch width.—About 10 cm.

Bunch weight (natural).—1,046 g.

Bunch weight (gibberellic acid treated).—1,533 g.

Bunch density.—Well-filled, but loose.

Number of berries.—172.

Form.—Elliptic.

Peduncle:

Length of peduncle.—About 10 cm.

Lignification of peduncle.—Medium.

Color.—5YR 5/6.

Berry:

Size.—Large.

Uniformity of size.—Uniform.

Berry weight (natural).—5.6 g.

Berry weight (gibberellic acid treated).—10.9 g.

Shape.—Natural: round; Gibberellic acid treated: obovate.

Presence of seeds.—Seedless; most berries develop 1 or 2 small, softrudimentary seeds less than 1 mm in length. Seeds are dark red, 5R 5/8.

Cross section.—Circular.

Dimensions.—Longitudinal axis about 1.5 cm.; horizontal axis about 2.3cm.

Skin color (without bloom).—5RP 3/2.

Coloration of flesh.—Translucent, 2.5GY 8/2.

Juiciness of flesh.—Very juicy.

Berry firmness.—Very firm.

Particular flavor.—Neutral, typical vinifera.

Bloom (cuticular wax).—Strong.

Pedicel length.7-10 mm.

Berry separation from pedicel.—Moderate.

Skin:

Thickness.—Medium.

Texture.—Tender.

Reticulation.—Absent.

Roughness.—Absent.

Tenacity.—Tenacious to flesh.

Tendency to crack.—Resistant.

Particular flavor.—Skins develop bitter flavor if exposed to sunlight.

What is claimed is:
 1. A new and distinct variety of grape plant named‘15-97-77’ as herein described, illustrated and identified by thecharacteristics enumerated above.